The Night Season, Cottesloe, NT, London

Annette Crosbie gives one of the best performances of the year in The Night Season, a new play by Rebecca Lenkiewicz. In the Kennedy household in Sligo, where three adult sisters live with their drunken dad, Crosbie plays dotty old Lily, the mother of the woman who abandoned this family 15 years earlier and decamped to London.

Lily can't remember the last time she was alone with a man. Now she's in terminal decline and Crosbie, who can summon up the spirit of a fierce, blue-eyed little girl, superbly conveys the disconcerting, almost indecent directness of this character's rage for life and her flustered worry that she is being patronised. "Nobody's paying you, are they? To dance with me?" she asks John, the handsome young film actor who is lodging with them while starring in a movie about Yeats and Maud Gonne, and who becomes the light of her last few weeks. There is no trace of the condescension her character dreads in either the writing or in Crosbie's wonderful portrayal.

At first, I thought the play was a going to be a severe case of déjà vu. Everything seemed to be a teasing theatrical reminder of something else - from the unsettling effects of a big budget film crew in rural Ireland (Stones in His Pockets) to the various affinities with Chekhov (not least the middle daughter's unhappy fling with a romantic visitor).

The alchoholic father of the three girls is beautifully played by David Bradley as a reprobate whose scathing cynicism has become a kind of family routine, and who fancies himself as an Irish King Lear - "No wonder he went fucking mad. And that was without the mother-in-law." Memories of Frank McGuinness and Brian Friel (among others) are similarly stirred.

But in the course of Lucy Bailey's splendidly acted production - which imparts a dream-like feel to the proceedings, with its spaced-out set, weird aerial angles, and torrential falls of sand for the seashore scenes - Lenkiewicz's more distinctive strengths become increasingly apparent. She has a gift for combining the lyrical and the eccentrically comic. She knows how to shape abrupt, resonant exchanges, as when John, the film actor, (John Light) tells Lily that "you're as old as you feel", and she surgically detaches the consolation from that cliché with "what if you feel nothing?".

The writer has shrewd psychological insights into the devastation caused when a mother walks out. One of the best scenes takes place in the pub: the oldest librarian-daughter Judith (superb Susan Lynch), who was left with the responsibilities, is taunted and cajoled by her father into breaking the habits of an orderly lifetime by embarking on a drinking contest with him.

When she has to cut short a desolating trip to her mother, Judith takes refuge with a former lover (Lloyd Hutchinson). The "will they, won't they?" nature of this strand is not one of the more original aspects of the piece. But, like the rest of The Night Season, it has a humour and humanity that suggest Lenkiewicz's next play will be even freer from influences.